1. Field of the Art
Embodiments of the present invention relate to three dimensional (“3D” or “3-D”) image rendering and three dimensional image displays using active-shutter glasses in general and, in particular, to the rendering and display of stereoscopic images at various degrees of roll to compensate for a viewer whose eyes are rotated with respect to images on a display.
2. Description of the Related Art
Three dimensional images are typically displayed to viewers through the process of stereoscopy, where a different perspective of an object or scene is presented to each eye of the viewer. This pair of stereoscopic images is seen by the eyes and combined in vision processing to create the illusion of depth. The general idea can be captured by the example of three dimensional glasses with red and blue lenses, where each lens filters out a respective color to present a different image to each eye, which results in the display of a three dimensional image. Other methods include rapidly blocking the vision of one eye while allowing the other eye of a viewer to see an image and then alternating. Active 3D glasses, with liquid crystal display (LCD) lenses that alternate between opaque and transparent states, are often used for this technique. Autostereoscopic techniques exist to present different images to each eye without the use of glasses.
In prior art implementations, a pair of stereoscopic images displayed to the viewer are presented such that the images as viewed are horizontally adjacent and horizontally separated so as to create an illusion of depth when combined. This horizontal orientation of the images assumes that a viewer is facing the display without any degree of roll in the viewer's eyes with respect to the display, such as if a viewer were laying on his or her side. The horizontal spacing of the pair of stereoscopic images also remains constant, even if there is yaw rotation of the viewer's eyes. Methods and systems for compensating for a rotated view are described in related International Patent Application No. PCT/US2010/045078, filed Aug. 10, 2010, cited above.
Some of the solutions for compensating for roll orientation of a view require a system-level implementation. Because the entire system, both the television and 3D glasses, are involved in the implementation, the possibility of incompatibilities between the television and 3D glasses is present. An additional problem with entire-system-level methods for implementations is that tying the solution to both a television and 3D glasses involves the expense of altering both.
There is a need in the art for less expensive 3D technologies that are available to a mass consumer market